High-Speed Power Meter

Transcription

1 High-Speed Power Meter P/N: PM-1600 User Guide CORPORATE HEADQUARTERS 400 Godin Avenue Vanier (Quebec) G1M 2K2 CANADA Tel.: Fax: EXFO AMERICA 4275 Kellway Circle, Suite 122 Addison TX, USA Tel.: Fax: EXFO EUROPE Le Dynasteur 10/12, rue Andras Beck Meudon la Forêt Cedex FRANCE Tel.: Fax: EXFO ASIAPACIFIC 151 Chin Swee Road #03-29, Manhattan House SINGAPORE Tel.: Fax: TOLL-FREE (USA and Canada) info@exfo.com 2004 EXFO Electro-Optical Engineering Inc. All rights reserved. Printed in Canada.

2 High-Speed Power Meter P/N: PM-1600 User Guide CORPORATE HEADQUARTERS 400 Godin Avenue Vanier (Quebec) G1M 2K2 CANADA Tel.: Fax: EXFO AMERICA 4275 Kellway Circle, Suite 122 Addison TX, USA Tel.: Fax: EXFO EUROPE Le Dynasteur 10/12, rue Andras Beck Meudon la Forêt Cedex FRANCE Tel.: Fax: EXFO ASIAPACIFIC 151 Chin Swee Road #03-29, Manhattan House SINGAPORE Tel.: Fax: TOLL-FREE (USA and Canada) info@exfo.com 2004 EXFO Electro-Optical Engineering Inc. All rights reserved. Printed in Canada.

3 High-Speed Power Meter PM-1600 If the equipment described herein bears the symbol, the said equipment complies with the applicable European Union Directive and Standards mentioned in the Declaration of Conformity. User Guide P/N: March 2002

4 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form, be it electronically, mechanically, or by any other means such as photocopying, recording, or otherwise, without the prior written permission of EXFO Electro-Optical Engineering Inc. (EXFO). Information provided by EXFO is believed to be accurate and reliable. However, no responsibility is assumed by EXFO for its use nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent rights of EXFO. EXFO s Commerce And Government Entities (CAGE) code under the North Atlantic Treaty Organization (NATO) is 0L8C3. The information contained in this publication is subject to change without notice EXFO Electro-Optical Engineering Inc. Words that EXFO considers trademarks have been identified as such. However, neither the presence nor absence of such identification affects the legal status of any trademark. Units of measurement in this document conform to SI standards and practices.

5 Contents Contents Certification Information... vi 1 Introducing the PM-1600 High-Speed Power Meter... 1 Front Panel...2 Back Panel...3 RS-232 Connector Pinout Safety Information... 5 Safety Conventions...5 General Safety Information...6 Laser Safety Information...6 Electrical Safety Information Getting Started with Your High-Speed Power Meter... 9 Turning the PM-1600 On and Off...9 Selecting a Menu or a Menu Option...10 Nulling Electrical Offsets Acquiring Power Measurements Setting a Display Mode...13 Measuring Absolute Power...14 Measuring Relative Power...16 Measuring Corrected Power...19 Displaying Averaged Measurement...22 Setting Measurement Range...22 Viewing Statistics...24 Managing the Wavelength List...25 Setting a Correction Factor...30 Setting Display Resolution...32 Setting Refresh Rate...34 Setting Sampling Rate...35 Choosing a Number of Measurements for Averaging...36 Saving a Setup Configuration...37 Recalling a Setup Configuration...38 Resetting the PM Storing and Recalling Power Measurements Storing Power Measurements Manually...41 Recalling Manually Stored Power Measurements...42 Erasing Manually Stored Power Measurements...43 High-Speed Power Meter iii

6 Contents 6 Programming Acquisitions...45 Programming Data Acquisitions...45 Programming Timed Acquisitions...46 Programming Triggered Acquisitions...49 Saving a Program Configuration...53 Recalling a Program Configuration Performing Typical Tests with Your PM Performing Absolute Power Measurements...56 Measuring Insertion Loss...57 Testing Instrument Linearity...58 Characterizing an Optical Switch...60 Using the External Trigger...63 Using the Analog Output Controlling the PM-1600 Automatically or Remotely...67 Setting Up the PM-1600 for Remote Control...68 Communication Parameters...69 Standard Status Data Structure...70 Command Structure...72 General Commands Quick Reference...73 Specific Commands Quick Reference...75 Error Messages...80 SCPI Management Errors (System Errors)...81 PM-1600 Error Messages Customizing the PM-1600 Display...83 Setting Backlight...83 Setting Display Contrast...84 Choosing Video Mode Maintenance...87 Cleaning the Front Panel...87 Cleaning Fixed Connectors...88 Cleaning Connectors Equipped with EUI/EUA Adapters...90 Cleaning EUI/EUA Adapters...92 Cleaning Detector Ports...94 Cleaning the Analog Output and External Trigger Ports...95 Replacing the Fuse...96 Recalibrating the Unit...97 Software Upgrade...97 iv PM-1600

7 Contents 11 Troubleshooting Finding Information on the EXFO Web Site Contacting the Technical Support Group Transportation Warranty General Information Liability Exclusions Certification Service and Repairs EXFO Service Centers Worldwide A Technical Specifications B Remote Control (SCPI) Commands General Commands Specific Commands Index High-Speed Power Meter v

8 Certification Information Certification Information F.C.C. Information Electronic test equipment is exempt from Part 15 compliance (FCC) in the United States, but EXFO makes reasonable efforts to ensure this compliance. Information Electronic test equipment is subject to the EMC Directive in the European Union. The EN61326 standard prescribes both emission and immunity requirements for laboratory, measurement, and control equipment. This unit has been tested and found to comply with the limits for a Class A digital device. Please refer to the Declaration of Conformity. CSA Information This unit received CSA certification under the model name GO. The CSA Certificate Number is The C-US indicator adjacent to the CSA Mark signifies that the product has been evaluated to the applicable ANSI/UL and CSA Standards, for use in the United States and Canada. Independent Laboratory Testing This unit has undergone extensive testing according to the European Union Directive and Standards. All pre-qualification tests were performed internally, at EXFO, while all final tests were performed externally, at an independent, accredited laboratory. This guarantees the unerring objectivity and authoritative compliance of all test results. Use of shielded remote I/O cables, with properly grounded shields and metal connectors, is recommended in order to reduce radio frequency interference that may emanate from these cables. vi PM-1600

9 Certification Information DECLARATION OF CONFORMITY Application of Council Directive(s): 73/23/EEC - The Low Voltage Directive 89/336/EEC - The EMC Directive Manufacturer s Name: EXFO ELECTRO-OPTICAL ENG. Manufacturer s Address: 465 Godin Avenue Vanier, Quebec Canada G1M 3G7 (418) Equipment Type/Environment: Industrial Scientific Equipment Trade Name/Model No.: PM-1600 High-Speed Power Meter Year of Conformity Assessment: 2001 Standard(s) to which Conformity is Declared: EN :1993/ A2:1995 Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use, Part 1: General Requirements. EN 55022:1994/ A2:1997 EN :1997 Limits and Methods of Measurement of Radio Disturbance Characteristics of Information Technology Equipment. Generic Immunity for Residential, Commercial, and Light Industrial nvironment E I, the undersigned, hereby declare that the equipment specified above conforms to the above Directive and Standards. Manufacturer Signature: Full Name: Stephen Bull, E. Eng Position: Vice-President Research and Development Address: 465 Godin Avenue Vanier, Quebec, Canada Date: November 15, 2001 High-Speed Power Meter vii

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11 1 Introducing the PM-1600 High-Speed Power Meter The PM-1600 High-Speed Power meter provides all the performance you need to increase your testing efficiency. With its high sampling rate and fast stabilization time, the PM-1600 is ideal for system monitoring and high-density WDM component characterization and assembly. The PM-1600 is available with one or two detectors. Each power channel (detector) is independently controlled (except for the acquisition frequency) and can achieve a sampling rate of up to 4096 Hz. Power transitions of up to 95 db will stabilize within 15 ms. Faster stabilization time will be achieved with reduced dynamic range. Stabilization within 1 ms is possible when the gain of the detector amplification stage is manually locked on a specific scale ( Manual Range ). Power measurement acquisitions can be electrically synchronized with the external trigger input or optically synchronized by programming a power level threshold. In addition to the standard, 1 mm InGaAs detector, the PM-1600 power meter series offers a new detector option, the PM-1600W wide-area detector. This power meter, equipped with a 3 mm diameter InGaAs detector, offers excellent repeatability for in-process testing of components before they are connectorized. Also, this large detector option improves the stabilization time of the module over the complete dynamic range. Particularly user-friendly with its state-of-the-art technology display, the PM-1600 features absolute power (in watts or dbm) and relative power (db or W/W) measurements, manual data storage, and programmed data acquisition. The PM-1600 is particularly suited for the most demanding laboratory, qualification, and manufacturing applications. It can be remotely controlled through a GPIB or RS-232 interface. High-Speed Power Meter 1

12 Introducing the PM-1600 High-Speed Power Meter Front Panel Front Panel Recall menu access see page 42 Display Program menu access see page 46 Setup menu access see page 18 Store menu access see page 41 Arrow buttons for menu navigation and parameter settings Offset nulling control see page 11 Reference control see page 16 PM-1600 HIGH-SPEED POWER METER Store Relative mode control see page 16 Recall Program Absolute mode control see page 14 Null Display ENTER Setup Analog Out C1 C2 Ext. Trig On/off button dbm/w db W/W Ref Chan λ Range Avg Shift Wavelength control see page 11 Power range control see page 22 Average mode control see page 22 Display mode control see page 13 Channel control (PM-1620) see page 13 Secondary function control Confirmation button External trigger port Channel #2 detector port Channel #1 detector port Analog output port Note: Your PM-1600 may slightly differ from the above illustration. 2 PM-1600

13 Introducing the PM-1600 High-Speed Power Meter Back Panel Back Panel GPIB port see page 67 Serial port (RS-232 DTE) see page 4 Fuse holder see page 96 Power inlet see page 8 GPIB IEEE SH1, AH1, T6, L4, SR1, RL1, PP0, DC1, DT1, C0, E2 Serial Port C MODEL: GO R LR US V 50/60 Hz 2 A F2AL250 V This device complies with part 15 of the FCC rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference and (2) this device must accept any interference received, including interference that may cause undesired operation. P/N Ver. S/N Made in Canada Mfg. date QST-151E Electro-Optical Engineering 465 Godin Ave. Vanier, Que., Canada G1M 3G7 Ground Part number P/N PM-1623 A-2.0 Ver. Version number Serial number S/N AB November 2001 Mfg. date Manufacturing Note: Your PM-1600 may slightly differ from the above illustration. High-Speed Power Meter 3

14 Introducing the PM-1600 High-Speed Power Meter RS-232 Connector Pinout RS-232 Connector Pinout The RS-232 connector (serial port) at the back of the PM-1600 uses a DTE pinout configuration Pin Description Direction 2 Receive (Rx) Input 3 Transmit (Tx) Output 5 Signal ground (Gnd) 4 PM-1600

15 2 Safety Information Safety Conventions You should understand the following conventions before using the product described in this manual: WARNING CAUTION Refers to a potential personal hazard. It requires a procedure which, if not correctly followed, may result in bodily harm or injury. Do not proceed beyond a WARNING unless you understand and meet the required conditions. Refers to a potential product hazard. It requires a procedure which, if not correctly followed, may result in component damage. Do not proceed beyond a CAUTION unless you understand and meet the required conditions. IMPORTANT Refers to any information regarding the operation of the product which you should not overlook. High-Speed Power Meter 5

16 Safety Information General Safety Information General Safety Information The following safety precautions must be observed during the operation and servicing of the units. Failure to comply with these precautions or with specific indications elsewhere in this manual violates safety standards of intended use of the unit. EXFO assumes no liability for the user's failure to comply with these requirements. This unit is intended for indoor use only. Unit covers cannot be removed during operation. The unit must be positioned in a way not to block the ventilation holes located on each side of the unit. Installation of replacement parts or modification of the unit should be carried out by authorized personnel only. Laser Safety Information WARNING Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. WARNING Do not install or terminate fibers while a laser source is active. Never look directly into a live fiber and ensure that your eyes are protected at all times. 6 PM-1600

17 Safety Information Electrical Safety Information Electrical Safety Information Before powering on the unit, all grounding terminals, extension cords, and devices connected to it should be connected to a protective ground via a ground socket. Any interruption of the protective grounding is a potential shock hazard and may cause personal injury. Whenever the ground protection is impaired, the unit is not to be used and must be secured against any accidental or unintended operation. Only fuses with the required rated current and specified type (IEC, 250 V, 2 A, fast blow,5 mm x 20 mm (0.197 in x in)) may be used for replacement. Do not use repaired fuses or short-circuited fuse holders. Any adjustments, maintenance, and repair of opened units under voltage should be avoided and carried out only by skilled personnel aware of the hazards involved. Do not attempt internal service or adjustment unless another person qualified in first aid is present. Do not replace any components while power cable is connected. Operation of any electrical instrument around flammable gases or fumes constitutes a major safety hazard. Capacitors inside the unit may be charged even if the unit has been disconnected from its electrical supply. AC Requirements The PM-1600 can operate from any single-phase AC power source between 100 V and 240 V (50 Hz/60 Hz). The maximum input current is 2 A. High-Speed Power Meter 7

18 Safety Information Electrical Safety Information Power Cable The PM-1600 s power cable is its disconnecting device. The PM-1600 uses an international safety standard three-wire power cable. This cable serves as a ground when connected to an appropriate AC power receptacle. The type of power cable supplied with each unit is determined according to the country of destination. Only qualified electricians should connect a new plug if needed. The color coding used in the electric cable depends on the cable. New plugs should meet the local safety requirements and include the following features: adequate load-carrying capacity ground connection cable clamp WARNING To avoid electrical shock, do not operate the unit if there are signs of damage to any part of the outer surface (covers, panels, etc.). To avoid serious injury, the following precautions must be observed before powering on the unit. If the unit is to be powered via an auto-transformer for voltage reduction, the common terminal must be connected to the grounded power source pole. Insert the plug into a power outlet with a protective ground contact. Do not use an extension cord without a protective conductor. Before powering on the unit, the protective ground terminal of the unit must be connected to a protective conductor using the unit power cord. Do not tamper with the protective ground terminal. 8 PM-1600

19 3 Getting Started with Your High-Speed Power Meter Turning the PM-1600 On and Off IMPORTANT Before turning the PM-1600 on, please read the Safety Information on page 5. To turn the unit on or off, use the red button in the lower left corner of the front panel. When you turn on the unit, it beeps twice and performs a self-test, while displaying startup information as well as the software version number. Before taking any measurements, it is recommended that you null the detector offsets (see Nulling Electrical Offsets on page 11). When the unit is turned off, the following items remain in non-volatile memory: manually stored data reference values remote-control settings shortlisted wavelengths customized settings saved configurations (up to three setup configurations and up to three program configurations) Note: To ensure the power is completely turned off, disconnect the power cord. High-Speed Power Meter 9

20 Getting Started with Your High-Speed Power Meter Selecting a Menu or a Menu Option Selecting a Menu or a Menu Option The PM-1600 is equipped with a new type of multifunctional, graphical liquid crystal display (LCD) with increased brightness, readability, and resolution that significantly improves both menu navigation and power meter operation versatility. For basic PM-1600 operation, simply press the control buttons at the bottom of the display. PM-1600 HIGH-SPEED POWER METER Store Recall Program Null Display ENTER Setup Analog Out C1 C2 Ext. Trig dbm/w db W/W Ref Chan λ Range Avg Shift To access a secondary function, press Shift (SH marker appears in the lower right corner of the display), then press the desired control button. To select a menu, press the matching menu button. For more information, see Storing and Recalling Power Measurements on page 41 and Customizing the PM-1600 Display on page 83. To select a menu option, use the up/down or left/right arrow keys until the desired option is highlighted, then confirm by pressing ENTER. To exit a menu, use the up/down or left/right arrow keys until Exit is highlighted, then press ENTER. You can also press the button that gave access to the menu. 10 PM-1600

21 Getting Started with Your High-Speed Power Meter Nulling Electrical Offsets Note: The PM-1600 will beep whenever the unit does not allow an operation. Note: In this manual, the single-channel power meter is referred to as the PM-1610 and the dual-channel power meter as the PM Nulling Electrical Offsets The Offset Nulling function provides a zero power measurement, thus eliminating the effects of electronic dark current. For best results and accuracy, ensure that offsets are nulled before each test session, each time the unit is turned on, or whenever environmental conditions change while the power meter is operating (temperature and humidity variations affect the performance of optical detectors). IMPORTANT Light must not reach the detector when nulling offsets. When the PM-1600 is turned on after a cold start, allow the unit to warm up for about 20 minutes (30 minutes for PM-1600W) until the electronics stabilize and can meet announced optical specifications. To perform a nulling, 1. Place the protective cap over the detector port on which a nulling has to be performed. 1 AUTO dbm λ nm 2 LR4 CF 1.26 W/W λ nm SH High-Speed Power Meter 11

22 Getting Started with Your High-Speed Power Meter Nulling Electrical Offsets 2. If necessary, select the desired channel (in the case of a PM-1620) by pressing Chan. In the above figure, channel #1 is currently selected. 3. Press Shift, then Null. The offset nulling process takes approximately 10 seconds. Once done, the unit returns to the previously active operation state. Note: If you are trying to perform an offset nulling with a protective cap improperly tightened on the detector port, the message Light detected will be briefly displayed. If so, ensure the protective cap is properly tightened and restart the offset nulling. Note: Offset nulling constants are retained until a new offset nulling is performed. 12 PM-1600

23 4 Acquiring Power Measurements Setting a Display Mode A typical display in power measurement mode might look as follows. Channel 1 display zone Channel 2 display zone Inactive channel Averaging mode active Sensitivity range (auto) active Active channel Sensitivity range (manual) active Correction factor active Offset indicator 1 AVG AUTO 2 LR4 CF O Power reading Display mode tab REF db dbm λ 1.26 db nm SH Reference value (channel #1) Current unit Current wavelength (channel #2) Secondary function indicator To set the display mode, i.e., the data type at the bottom of the display, 1. If necessary, select the desired channel (PM-1620) by pressing Chan. The current wavelength is displayed for the active channel. In the above figure, channel #2 is currently selected. 2. Press Shift, then Display. The current reference value is displayed for the active channel (in dbm or W units, depending on the currently selected measurement unit). High-Speed Power Meter 13

24 Acquiring Power Measurements Measuring Absolute Power 3. Press Shift a second time, then Display. The current correction factor (CF) is displayed for the active channel (in db or W/W units, depending on the currently selected measurement unit). 4. Press Shift again, then Display. The Offset value (O) appears for the active channel (in db or W/W units, depending on the currently selected measurement unit). Note: On a PM-1610 single-channel power meter, two different data types simultaneously appear at the bottom of the display. To select the desired display mode, just press Display. Measuring Absolute Power When in absolute power, measured values are displayed in either dbm or W units (pw, nw, µw, mw...) according to the power of the signal, and the displayed value represents the absolute optical power reaching the detector within specified uncertainty. 1 AUTO 2 LR2 CF Power reading dBm nm λ λ 1.26 W/W nm SH Current wavelength Measurement unit To display absolute power, 1. If necessary, select the desired channel (PM-1620). In the above figure, channel #1 is currently selected. 14 PM-1600

25 Acquiring Power Measurements Measuring Absolute Power 2. If necessary, press λ to select the appropriate wavelength from the shortlist (see the section on viewing wavelength list on page 25). Note: The wavelength may take some time to change on the display due to a low refresh rate. To set the refresh rate, see Setting Refresh Rate on page Press dbm/w to display the absolute power of the signal received at the detector port. The dbm/w button is also used to toggle between dbm and W measurement units. An absolute power measurement in negative W units indicates that electrical offsets were improperly nulled. If so, repeat the offset nulling (see Nulling Electrical Offsets on page 11). Note: When is displayed, the power level detected is below the lower limit of the selected measurement range. When is displayed, the power level detected is above the upper limit of the selected measurement range. See Setting Measurement Range on page 22. When!!!!!!! is displayed, the displayed data is in transition (range was changed in power measurement mode, with Autorange selected). When * ******is displayed, a programmed acquisition is running with a high sampling rate. High-Speed Power Meter 15

26 Acquiring Power Measurements Measuring Relative Power Measuring Relative Power Power measurements can be displayed as a deviation from an absolute reference value. The relative power is particularly useful when performing insertion loss measurements. Relative power is displayed in db when the reference value is measured in dbm. If this is the case, the value will either be positive or negative since the actual measured power is higher or lower than the reference power. If the reference value is in W, the relative power will be displayed in W/W units. The relative power will then represent the deviation ratio from the reference. Relative power unit 1 AUTO CF Relative power λ nm REF db dbm SH Current wavelength Reference value Reference unit In the example on the previous page, the measured power is db higher than the reference value of dbm. The absolute power is dbm. To display relative power, 1. If necessary, select the desired channel (PM-1620). 2. If necessary, press λ to select the appropriate wavelength from the shortlist (see the section on viewing wavelength list on page 25). 16 PM-1600

27 Acquiring Power Measurements Measuring Relative Power 3. Press db/w/w until the display switches to relative mode in db (where the value displayed is equal to the absolute power minus the previously stored reference power) or in W/W (where the value displayed is the deviation ratio from the reference). Pressing db/w/w again switches between db and W/W measurement units for the relative power and reference value. When you access relative mode, the PM-1600 displays the last reference value entered at the current wavelength (to view the reference value, set the appropriate channel to reference display mode). However, to display meaningful relative power readings, it is important to have an appropriate reference value, using appropriate adapters and test jumpers, and connecting the optical circuit being referenced to a detector port. Note: If you set a reference while a correction factor (CF) is active, the reference measurement will take the correction factor into account. To set a reference value, two choices are available. Entering the Current Power as the Reference Value To enter the current power, 1. If necessary, select the desired channel (PM-1620). 2. If necessary, press λ to select the appropriate wavelength. 3. Press dbm/w to select the desired measurement unit. 4. Press Ref to use the current power value as the new reference. Note: Pressing Ref switches the display to relative mode. High-Speed Power Meter 17

28 Acquiring Power Measurements Measuring Relative Power Entering a Specific Reference Value To enter a specific value, 1. If necessary, press λ to select the appropriate wavelength. 2. Press dbm/w to select the desired measurement unit. 3. Press Setup to access the Setup menu. System Setup Wavelength List & Corr. Factor Channel 1 Setup Channel 2 Setup Exit 4. Use the up/down arrow keys to select Channel 1 Setup or Channel 2 Setup, then press ENTER. The current channel settings are displayed. 5. Use the up/down arrow keys to select Reference. Resolution Averaging db (Active) Reference dbm Reset Offset db Reset Exit Channel 1 Setup 5a. To clear the current reference, use the left/right arrow keys to select Reset, then confirm by pressing ENTER. 18 PM-1600

29 Acquiring Power Measurements Measuring Corrected Power 5b. To modify the current reference, press ENTER to select the reference edit box, then use the left/right arrow keys to select the desired sign and digit, and the up/down arrow keys to increase or decrease the flashing value. Confirm by pressing ENTER. You can enter a reference value from dbm to dbm or from pw to kw. Note: You can toggle between dbm and W units while in the Channel Setup menu by pressing dbm/w. 6. Exit the Channel Setup menu and then the Setup menu. Measuring Corrected Power A correction factor (CF) can be applied to any measurement that is displayed in either db, dbm, W, or W/W units. When expressed in db, the correction factor, which can be positive or negative, is applied to the measured power. When expressed in W/W, the correction factor is a deviation from the measured power. This feature provides additional flexibility and can be useful when compensating for known inaccuracies (power gains or losses) at specific wavelengths. To use the corrected power display, see Setting a Correction Factor on page 30. When a correction factor is active, i.e., different from db or W/W, the CF marker appears at the top of the display for the matching channel. Note: Special care must be taken when setting a correction factor as it emulates a new calibration (the PM-1600's calibration is not affected and will be restored by setting the CF back to a null value). High-Speed Power Meter 19

30 Acquiring Power Measurements Measuring Corrected Power Setting an Offset Value You can use the Offset function to take into account, in the power displayed, of a known gain or loss in the link that is not already included in the signal reaching the detector. Contrary to the correction factor, which applies to a specific wavelength, the offset value applies to any wavelength when it is enabled on a specific channel. To enter an offset value, 1. If necessary, press λ to select the appropriate wavelength. 2. Press dbm/w to select the desired measurement unit. 3. Press Setup to access the Setup menu. System Setup Wavelength List & Corr. Factor Channel 1 Setup Channel 2 Setup Exit 4. Use the up/down arrow keys to select Channel 1 Setup or Channel 2 Setup, then press ENTER. The current channel settings are displayed. 20 PM-1600

31 Acquiring Power Measurements Measuring Corrected Power 5. Use the up/down arrow keys to select Offset. Resolution Averaging db (Active) Reference dbm Reset Offset db Reset Exit Channel 1 Setup 5a. To clear the current offset, use the left/right arrow keys to select Reset, then confirm by pressing ENTER. 5b. To modify the current offset, press ENTER to select the offset edit box, then use the left/right arrow keys to select the desired sign and digit, and the up/down arrow keys to increase or decrease the flashing value. Confirm by pressing ENTER. You can enter an offset value from dbm to dbm or from pw to kw. Note: The Offset value will be displayed in db or W/W units, depending on the currently selected measurement unit. Note: You can toggle between dbm and W units while in the Channel Setup menu by pressing dbm/w. 6. Exit the Channel Setup menu and then the Setup menu. High-Speed Power Meter 21

32 Acquiring Power Measurements Displaying Averaged Measurement Displaying Averaged Measurement To display averaged power measurement, 1. If necessary, select the desired channel (PM-1620). 2. Press Avg. When averaging is enabled, the AVG marker appears at the top of the display for the matching channel. The most recent measurement samples, of which the number is set in the System Setup menu (see Choosing a Number of Measurements for Averaging on page 36), are then used to compute an unweighted average. Setting Measurement Range The measurement range (or gain scale) applied to the power measurement detector can be manually selected to prevent the automatic scale adjustment performed by the instrument. A manual adjustment of the dynamic gain scale will lock the measurement range to a specific level. The measurement range should be locked when the analog output (see Using the Analog Output on page 65) is used to avoid variations in voltage output due to scale changes. It is also necessary to use a manual range to achieve high-rate, programmed acquisitions (see Programming Data Acquisitions on page 45). Two types of manual ranges are available: The Low range provides a lower dynamic range (typically 22 db) per scale with better signal-to-noise ratio and resolution. The High range provides a higher dynamic range (typically 42 db) per scale with an inferior signal-to-noise ratio. In the PM-1620 model, each channel is adjusted independently. 22 PM-1600

33 Acquiring Power Measurements Setting Measurement Range To set the measurement range, 1. If necessary, select the desired channel (PM-1620). 2. Press Range until the required measurement range marker is shown at the top of the display for the matching channel. The table shown below displays the permitted manual ranges when the currently selected measurement unit is db or dbm. The power range values displayed are typical at 1310 nm. Low Range (LR) High Range (HR) 3.90 to dbm (LR1) a to dbm (HR1) a to 9.90 dbm (LR2) a to 9.90 dbm (HR2) a to dbm (LR3) to dbm (HR3) to dbm (LR4) to dbm (HR4) to dbm (LR5) to dbm (LR6) a. InGaAs detector has a +9 dbm saturation limit. Note: Select a manual range in power measurement mode when the input signal has unstable or modulated variations. This prevents!!!!!!! from being displayed upon constantly changing gain scales. High-Speed Power Meter 23

34 Acquiring Power Measurements Viewing Statistics Viewing Statistics Although it is not possible to retrieve acquisition results from the PM-1600 except when using remote control, this function provides you with statistical information on the last acquisition performed. To view statistics, 1. Press Program to access the Program menu. 2. Use the up/down or left/right arrow keys to select Statistics. 3. Confirm by pressing ENTER. The last statistics available are displayed. Min. Max. Mean Stdev dbm dbm dbm db n W /W n W /W n W /W n W /W Reject Exit % 0.00 % Note: Reject indicates the percentage of values rejected during measurements. When!!!!!!! is displayed, the displayed data is in transition. When is displayed, the power level detected is below the lower limit of the selected measurement range. When is displayed, the power level detected is above the upper limit of the selected measurement range. 24 PM-1600

35 Acquiring Power Measurements Managing the Wavelength List Managing the Wavelength List To view the list, 1. Press Setup to access the Setup menu. System Setup Wavelength List & Corr. Factor Channel 1 Setup Channel 2 Setup Exit 2. Use the up/down arrow keys to select Wavelength List & Corr. Factor, then press ENTER. The number of wavelengths in the list is displayed. If the maximum number of wavelengths (32) in the list is reached, full is displayed. If the list is empty, empty is displayed. A mark is displayed next to the active wavelength to indicate that it is on the wavelength list. Sampling View λ List (31 λ) Sort λ Del All λ nm Add λ Del λ Active wavelength CF Ch1 CF Ch W/W db Clear CF Clear CF Exit High-Speed Power Meter 25

36 Acquiring Power Measurements Managing the Wavelength List 3. Press ENTER. The wavelength list is displayed with the correction factor (CF) set for each wavelength on the list (for both channels in a PM-1620). Note: By default, the six most commonly used wavelengths (850 nm, 980 nm, 1310 nm, 1480 nm, 1550 nm, and 1625 nm)are saved in the wavelength shortlist. λ # λ (nm) CF Ch1 (W/W) CF Ch2 (db) Note: The correction factor is displayed in W/W or db depending on the currently selected measurement unit. 4. Use the up/down arrow keys to scroll through the wavelength list. 5. To exit the wavelength list, press ENTER. Note: A wavelength list can be set for each different setup configuration (up to three setup configurations are possible). To save or recall a setup configuration, see Saving a Setup Configuration on page 37, or Recalling a Setup Configuration on page PM-1600

37 Acquiring Power Measurements Managing the Wavelength List To sort the list by wavelengths, 1. Press Setup to access the Setup menu. 2. Use the up/down arrow keys to select Wavelength List & Corr. Factor. 3. Press ENTER. 4. Use the left/right arrow keys to select Sort λ. 5. Confirm by pressing ENTER. The wavelengths are sorted in ascending order. Note: If the list of wavelengths is full, delete a wavelength before adding a new one. See section on deleting a wavelength on page 29. To add a wavelength to the list, 1. Press Setup to access the Setup menu. 2. Use the up/down arrow keys to select Wavelength List & Corr. Factor. 3. Press ENTER. 4. Use the up/down arrow keys to select λ. 5. With λ highlighted, use the left/right arrow keys to select Add λ, then confirm by pressing ENTER. The current wavelength is displayed in the wavelength edit box. 6. Use the left/right arrow keys to select the flashing digit of the wavelength and the up/down keys to increase or decrease the flashing digit. You can enter a value with a 0.01 nm resolution. 7. Confirm the new wavelength by pressing ENTER. Note: Adding a wavelength to the list will not affect the current wavelength in measurement mode. High-Speed Power Meter 27

38 Acquiring Power Measurements Managing the Wavelength List To modify a wavelength, 1. Follow steps 1 to 4 in section on viewing the wavelength list on page 25. Select the wavelength to be modified by pressing ENTER. 2. Use the up/down arrow keys to select λ. 3. Press ENTER. 4. Use the left/right arrow keys to select the flashing digit of the wavelength and the up/down keys to increase or decrease the flashing digit. You can enter a value with a 0.01 nm resolution. Note: The mark in the wavelength edit box indicates that the wavelength is on the wavelength list. This mark may disappear as you modify the value in the wavelength edit box. 5. Confirm by pressing ENTER. 28 PM-1600

39 Acquiring Power Measurements Managing the Wavelength List To delete a specific wavelength from the list, 1. Follow steps 1 to 4 in section on viewing the wavelength list on page 25. Select the wavelength to be deleted by pressing ENTER. Note: You can also select the wavelength while in the Wavelength List & Corr. Factor menu by pressing λ. 2. With the wavelength to be deleted displayed in the wavelength edit box, use the up/down arrow keys to select λ. 3. Use the left/right arrow keys to select Del λ. 4. Confirm the wavelength deletion by pressing ENTER. To remove all the wavelengths from the list, 1. Press Setup to access the Setup menu. 2. Use the up/down arrow keys to select Wavelength List & Corr. Factor. 3. Press ENTER. 4. Use the left/right arrow keys to select Del All. 5. Confirm the wavelength list deletion by pressing ENTER. High-Speed Power Meter 29

40 Acquiring Power Measurements Setting a Correction Factor Setting a Correction Factor Applying a correction factor to the measured power is useful when compensating for known inaccuracies (power gains or losses). When a db correction factor other than is defined, the displayed power is equal to the actual power plus the value of the correction factor. When a W/W correction factor other than is defined, the displayed power is equal to the actual power times the value of the correction factor. With an active correction factor, the CF marker appears at the top of the display for the matching channel. Note: Setting a correction factor emulates a new calibration (the PM-1600's calibration is not affected and will be restored by setting back the CF to a null value). When expressed in db, the correction factor can be a positive or negative value. When the currently selected measurement unit is W, the correction factor is expressed in W/W, indicating a multiplication factor for the current wavelength and channel. The correction factor expressed in W/W will always be a positive value. To select a correction factor, 1. Press λ to select the appropriate wavelength, then Setup to access the Setup menu, then use the up/down arrow keys to select Wavelength List & Corr. Factor, and press ENTER. Or Follow steps 1 to 4 in section on viewing the wavelength list on page 25. Select the wavelength by pressing ENTER. Note: You can also select the wavelength while in the Wavelength List & Corr. Factor menu by pressing λ. 2. Use the up/down arrow keys to select CF Ch 1 or CF Ch 2 (PM-1620). The current correction factor for the matching wavelength is displayed in db or W/W, depending on the currently selected measurement unit. 30 PM-1600

41 Acquiring Power Measurements Setting a Correction Factor Note: You can toggle between db and W/W units while in the Wavelength List & Corr. Factor menu by pressing db/w/w. View λ List (26 λ) λ nm CF Ch W/W CF Ch db Exit Sort λ Add λ Clear CF Clear CF Del All Del λ 3. Press ENTER. 4. Use the left/right arrow keys to select the flashing digit of the correction factor and the up/down keys to increase or decrease the flashing digit. You can enter a value from db to db or from W/W to W/W. 5. Confirm the correction factor by pressing ENTER. The newly defined correction factor will be automatically applied when you return to measurement mode, with the CF marker at the top of the display for the matching channel. Note: Although the wavelength list applies to all channels, the correction factor applies to the specific wavelength and channel at which it was set. High-Speed Power Meter 31

42 Acquiring Power Measurements Setting Display Resolution To delete a correction factor, 1. Press λ to select the appropriate wavelength, then Setup to access the Setup menu, then use the up/down arrow keys to select Wavelength List & Corr. Factor, and press ENTER. Or Follow steps 1 to 4 in section on viewing the wavelength list on page 25. Select the wavelength by pressing ENTER. Note: You can also select the wavelength while in the Wavelength List & Corr. Factor menu by pressing λ. 2. Use the up/down arrow keys to select CF Ch 1 or CF Ch 2 (PM-1620). The current correction factor for the matching wavelength is displayed in db or W/W, depending on the currently selected measurement unit. Note: You can toggle between db and W/W units while in the Wavelength List & Corr. Factor menu by pressing db/w/w. 3. Use the left/right arrow keys to select Clear CF. 4. Confirm the deletion by pressing ENTER. The correction factor is immediately reset to db or W/W and, therefore, deactivated. Setting Display Resolution Depending on the required resolution and operating power level 0, 1, 2, 3, or 4 digits can be displayed after the decimal point. When AUTO is selected, the display resolution is determined by the power level being measured. Note: The AUTO marker on the display in measurement mode does not refer to the automatic display resolution but to the measuring range (see Setting Measurement Range on page 22). 32 PM-1600

43 Acquiring Power Measurements Setting Display Resolution To set the display resolution of a power measurement expressed in db or dbm, 1. Press Setup to access the Setup menu. 2. Use the up/down arrow keys to select Channel 1 Setup or Channel 2 Setup (PM-1620), then press ENTER. The current resolution is displayed with the current power measurement in real time. Current display resolution Current power measurement and unit Resolution dbm Averaging Reference Offset 002 (Inactive) dbm db Reset Reset Exit Channel 2 Setup 3. Press ENTER to access the display resolution edit box. 4. Use the up/down arrow keys to change the display resolution. The power measurement is immediately affected as can be seen in the display resolution edit box. 5. Press ENTER to confirm the new display resolution. Note: You can toggle between dbm and W units while in the Channel Setup menu by pressing dbm/w. Note: When W is selected, the display resolution changes to AUTO (different W units will be used according to the power of the signal detected). It is then impossible to access the display resolution edit box. High-Speed Power Meter 33

44 Acquiring Power Measurements Setting Refresh Rate Setting Refresh Rate This function allows you to define the refresh rate of the power readings in power measurement mode (for both channels in a PM-1620 dual-channel power meter). To set the refresh rate, 1. Press Setup to access the Setup menu. 2. Press ENTER to access the System Setup menu. 3. Use the up/down arrow keys to select Refresh Rate. The current refresh rate is displayed. Sampling Rte 256Hz RS232 / GPIB GPIB Refresh Rate 16Hz GPIB Addr. 15 Backlight ON Save # 3 Contrast Recall # 3 Video Mode STD Exit 4. Press ENTER to access the refresh rate edit box. 5. Use the up/down arrow keys to set the refresh rate between 1/2 Hz, 1Hz, 2Hz, 4Hz, 8Hz, and 16Hz. 6. Press ENTER to confirm the new refresh rate. 34 PM-1600

45 Acquiring Power Measurements Setting Sampling Rate Setting Sampling Rate This function allows you to define the number of power readings per second in power measurement mode (for both channels in a PM-1620 dual-channel power meter) with a maximum of 256 per second. In power measurement mode, power measurements are constantly updated on the measurement display. Samples can also be retrieved with the GPIB or RS-232 interface (refer to the IQ-200 GPIB and Application Development Guide). According to your specific requirements and the power level, you will select a sampling rate that will optimize instrument flexibility and measurement stability as well as determine the quantity of data generated during data acquisition. Note: Use a lower sampling rate with averaging active (see Displaying Averaged Measurement on page 22) for greater repeatability when measuring very low power. To set the sampling rate, 1. Press Setup to access the Setup menu. 2. Press ENTER to access the System Setup menu. The current sampling rate is displayed. 3. Press ENTER to access the sampling rate edit box. 4. Use the up/down arrow keys to select the rate from the 11 values listed. Values vary from 1/4 Hz to 256 Hz. 5. Press ENTER to confirm the new sampling rate. If using a PM-1620 dual-channel power meter, the sampling rate applies to both channels. Note: The sampling rate defined in the Setup menu is independent of the sampling rate defined in the Program menu. High-Speed Power Meter 35

46 Acquiring Power Measurements Choosing a Number of Measurements for Averaging Choosing a Number of Measurements for Averaging Power measurements can be averaged over a programmable number of samples by pressing Avg in power measurement mode. Measurements will continue to be displayed at the specified sampling and refresh rates (see Setting Sampling Rate on page 35 and Setting Refresh Rate on page 34), but the average will include the specified number of power samples. To set the number of measurements for averaging, 1. Press Setup to access the Setup menu. 2. Use the up/down arrow keys to select Channel 1 Setup or Channel 2 Setup (PM-1620), then press ENTER. 3. Use the up/down arrow keys to select Averaging. The current averaging number is displayed with the averaging status (Active or Inactive). 4. Press ENTER to access the averaging number edit box. 5. Use the left/right arrow keys to select the flashing digit of the averaging number and the up/down keys to increase or decrease the flashing digit. You can enter a value from 002 to Press ENTER to confirm the new number of measurements for averaging. Note: You can activate or deactivate the averaging function while in the Channel Setup menu by pressing Avg. 36 PM-1600

47 Acquiring Power Measurements Saving a Setup Configuration Saving a Setup Configuration Once the PM-1600 has been customized for a specific application or user, it is possible to save the configuration of the parameters that have been set in the Setup menu, with the exception of the contrast setting. Up to three setup configurations can be saved and recalled. The following parameters are saved: channel parameters (measurement unit, display resolution, averaging status and number, measuring range, reference value, active wavelength, correction factor, and display mode) system parameters (sampling rate, refresh rate, backlight, video mode, RS-232/GPIB address, wavelength shortlist, active channel, and active program) To save a setup configuration, 1. Press Setup to access the Setup menu. 2. Press ENTER to access the System Setup menu. 3. Use the up/down or left/right arrow keys to select Save. The current setup configuration number is displayed. Note: (Mod.) indicates that a recalled setup configuration has been modified. 4. Press ENTER to access the setup configuration number edit box. 5. Use the up/down arrow keys to set a setup configuration number from 1 to Confirm the new setup configuration by pressing ENTER. It takes a few seconds to save a setup configuration. High-Speed Power Meter 37

48 Acquiring Power Measurements Recalling a Setup Configuration Recalling a Setup Configuration Once you have saved a setup configuration, you can recall it at any time. To recall a configuration, 1. Press Setup to access the Setup menu. 2. Press ENTER to access the System Setup menu. 3. Use the up/down or left/right arrow keys to select Recall. The current setup configuration number is displayed. 4. Press ENTER to access the setup configuration number edit box. 5. Use the up/down arrow keys to select the required configuration number. 6. Confirm by pressing ENTER. It takes a few seconds to recall a setup configuration. 38 PM-1600

49 Acquiring Power Measurements Resetting the PM-1600 Resetting the PM-1600 When turning on the unit, press ENTER until the unit beeps repeatedly. All the user-defined parameters are reset to their default values. These are displayed in the following tables. Channel Parameters Measurement unit Display resolution Averaging Number of measurements used for averaging Measuring range Reference Offset Wavelength Correction factor Display mode W AUTO Active 2 Autorange Null Null 850 nm OFF Reference High-Speed Power Meter 39

50

51 5 Storing and Recalling Power Measurements Storing Power Measurements Manually The PM-1600 has 100 memory registers to manually store absolute or relative power measurements (for both channels in a PM-1620). To store a measurement manually, select the desired measurement and then press Store. The register number is briefly displayed. Register number 1 AUTO 2 LR4 CF M dBm nm λ λ 1.26 W/W nm SH Note: The register number automatically increases each time you store a measurement. When the maximum number of 100 power measurements is reached, it is no longer possible to store new power measurements. Full is then displayed. Note: You may observe a difference between the power measurement displayed and the power measurement stored, especially if the sampling rate is significantly higher than the refresh rate. High-Speed Power Meter 41

52 Storing and Recalling Power Measurements Recalling Manually Stored Power Measurements Recalling Manually Stored Power Measurements The power measurements that you stored manually (see Storing Power Measurements Manually on page 41) can be recalled one register at a time. To retrieve a manually stored power measurement, 1. Press Recall. The display either indicates the number of stored power measurements or a message stating whether the memory is empty or full. View Stored Data (27 values) Erase Stored Data Exit 2. Press ENTER. A stored power measurement is displayed with the matching register number. 3. Use the up/down arrow keys to select the required register. Note: You can keep the up/down arrow keys pressed to quickly scan the power measurements in adjacent registers. To speed up the scan, use the left/right arrow keys. 4. To exit the Recall menu, press Recall, or select Exit then press Enter. When recalling a stored power measurement, it is possible to change the display mode (on both channels when using a PM-1620) and the measurement unit. 42 PM-1600

53 Storing and Recalling Power Measurements Erasing Manually Stored Power Measurements Erasing Manually Stored Power Measurements The manually stored power measurements (up to 100) can be erased as a batch. To erase a stored power measurement, 1. Press Recall. 2. Use the up/down arrow keys to select Erase Stored Data. IMPORTANT After you press ENTER, all the manually stored power measurements in the 100 registers will be deleted without any other warning. 3. Press ENTER to confirm the deletion. It takes a few seconds to erase all stored power measurements. 4. To exit the Recall menu, press Recall, or select Exit then press Enter. High-Speed Power Meter 43

54

55 6 Programming Acquisitions Programming Data Acquisitions In addition to measurement mode (where power measurements are constantly updated on the display) and to manually stored power measurements, the PM-1600 allows either timed or triggered programmed acquisitions. Here, absolute or relative power measurements are acquired for a fixed number of samples, thus for a fixed duration at a specific sampling rate and stored in the PM-1600 s RAM. With programmed acquisitions, it is possible to use the same sampling rates as the ones defined in the Setup menu (i.e., from 1/4 Hz to 256 Hz), as well as higher sampling rates (from 512 Hz to 4096 Hz). Both types of available sampling rates are displayed in the following table.. Low a High Programmed Acquisition Sampling Rate 1/4Hz, 1/2Hz, 1Hz, 2Hz, 4 Hz, 8 Hz, 16 Hz, 32 Hz, 64 Hz, 128 Hz, and 256 Hz 512 Hz, 1024 Hz, 2048 Hz, and 4096 Hz Maximum Number of Points PM-1610 PM (per channel) (per channel) a. Low acquisition rates are also available in power measurement mode. A manual range (see Setting Measurement Range on page 22) must be set, on both channels when using a PM-1620, to perform a programmed acquisition. The sampling rate defined in the Program menu is independent of the sampling rate defined in the Setup menu. The two types of programmed acquisitions (timed acquisition and triggered acquisition) are described hereafter. High-Speed Power Meter 45

56 Programming Acquisitions Programming Timed Acquisitions Programming Timed Acquisitions A timed acquisition is enabled as soon as Start Program is pressed and continues for the time specified in the duration edit box or until the specified number of points has been acquired. If a delay was set in the delay edit box, the acquisition will start once the countdown has expired. If no delay was set, the acquisition will start immediately after Start Program is pressed. To program a timed acquisition, 1. Set the power measurement parameters as required (see Customizing the PM-1600 Display on page 83). 2. Press Program to access the Program menu. The default program parameters are displayed. Trigger Inactive must be displayed. Trigger Inactive Delay Duration Sampling Points 00h00m00s 00h00m00s 1Hz 0000/Ch. Statistics Save # 1 Recall # 1 Start Program Exit Note: If you do not want the acquisition to be delayed, skip step To delay the acquisition, 3a. Use the up/down or left/right arrow keys to select Delay. 3b. Press ENTER to access the delay edit box. 3c. Use the left/right arrow keys to select the flashing digit of the delay and the up/down keys to increase or decrease the flashing digit. You can enter a delay from 00h00m01s to 99h59m59s. 3d. Confirm the delay by pressing ENTER. 46 PM-1600

57 Programming Acquisitions Programming Timed Acquisitions 4. Use the up/down or left/right arrow keys to select the sampling rate as per table on page 45, and confirm by pressing ENTER. If you want to set the number of points for the acquisition instead of the duration, skip step Set the duration of the acquisition: 5a. Use the up/down or left/right arrow keys to select Duration. 5b. Press ENTER to access the duration edit box. 5c. Use the left/right arrow keys to select the flashing digit of the duration and the up/down keys to increase or decrease the flashing digit. You can enter a duration from 00h00m01s to 99h59m59s (the maximum duration allowed depends on the sampling rate and on the maximum number of points. See table on page 45). As you change the duration, the number of points is automatically set as a function of the sampling rate. 5d. Confirm the duration by pressing ENTER. 6. Set the number of points for the acquisition: 6a. Use the up/down or left/right arrow keys to select Points. 6b. Press ENTER to access the points edit box. 6c. Use the left/right arrow keys to select the desired digit and the up/down arrows to increase or decrease the flashing value. Then confirm by pressing ENTER. See table on page 45 for the maximum number of points that can be set. As you change the number of points, the duration is automatically set as a function of the sampling rate. High-Speed Power Meter 47

58 Programming Acquisitions Programming Timed Acquisitions 7. Press Start Program to enable the acquisition. Once the acquisition is enabled, you can disable it by selecting Stop Program and pressing ENTER. Note: Once you have enabled the acquisition, you can see how much time is left in the delay (before the acquisition actually starts) and how much time is left in the acquisition from within the Program menu. 8. You can exit the Program menu and return to measurement mode either by pressing Program, or by selecting Exit then pressing ENTER. In measurement mode, PG is shown in the upper right corner of the display. Although you can revert to the Program menu, no action is possible in measurement mode until the acquisition has been completed. When the acquisition is completed, the PG marker disappears. Data processing is performed, which takes a few seconds, then the PM-1600 returns to measurement mode. 48 PM-1600

59 Programming Acquisitions Programming Triggered Acquisitions Programming Triggered Acquisitions Conditional data acquisition can be performed by using a triggered acquisition, where data recording begins when a specified condition is met and continues until the specified number of points has been acquired or for the time specified in the duration edit box. If a delay was set in the delay edit box, the acquisition will not start until the countdown has expired, and then the specified condition is met. Different trigger conditions are available. These conditions are explained in the following table. Trigger Power > Level or Power < Level (channel #1 or channel #2) Falling Edge or Rising Edge (external trigger) Description Acquisition will start when the measured power is greater or smaller than the specified power level (in dbm or W units). Acquisition will be triggered by an external signal on the external trigger port of the power meter, whether on negative or positive TTL transitions. See also Using the External Trigger on page 63. Note: The trigger defines the condition for starting data acquisition. Once underway, the acquisition will continue until the specified number of points has been acquired or for the specified duration, regardless of the measured power. High-Speed Power Meter 49

60 Programming Acquisitions Programming Triggered Acquisitions To program a triggered acquisition, 1. Set the power measurement parameters as required (see Customizing the PM-1600 Display on page 83). 2. Press Program to access the Program menu. 3. You can set a delay as explained on page Use the up/down or left/right arrow keys to select the sampling rate (as per table on page 49), and confirm by pressing ENTER. 5. To set the trigger, press ENTER to access the trigger menu. 5a. To activate the trigger, Press ENTER to access the trigger status edit box. Use the up/down arrow keys to activate the trigger, then confirm by pressing ENTER. The default trigger parameters are displayed. Status Active Trig. Rising Edge Source Ext. Trig Level N.A. Exit Use the up/down or left/right arrow keys to select Trig. 5b. To set the trigger source, Use the up/down or left/right arrow keys to select Source. Press ENTER to access the source edit box. Use the up/down arrow keys to define whether the acquisition will be externally triggered or started when channel #1 or #2 (PM-1620) receives a signal. The power level of this signal will be set in step 5d. Note: An externally triggered acquisition is only possible using a high sampling rate. 50 PM-1600

61 Programming Acquisitions Programming Triggered Acquisitions 5c. To set the trigger type, Press ENTER to access the trigger edit box, i.e., to define whether the acquisition will be triggered by an external signal on positive (rising edge) or on negative (falling edge) TTL voltage transitions using the external trigger or be started when the measured power on channel #1 or #2 is greater or smaller than the specified power level. Use the up/down arrow keys to select Rising Edge or Falling Edge, then confirm by pressing ENTER. 5d. To set the trigger level, If you selected Chann. 1 or Chann. 2, use the up/down or left/right arrow keys to select Level. Press ENTER to access the trigger level edit box. Use the left/right arrow keys to select the desired sign and digit and the up/down arrows to increase or decrease the flashing value. Then confirm by pressing ENTER. You can enter a trigger level from dbm to dbm or from pw to kw. The trigger level must be set in absolute power measurement mode (see Measuring Absolute Power on page 14) and must be within the range of the active channel (see Setting Measurement Range on page 22). Note: You can toggle between dbm and W units from within the trigger menu by pressing dbm/w. Confirm the trigger power level by pressing ENTER, then exit the trigger menu. High-Speed Power Meter 51

62 Programming Acquisitions Programming Triggered Acquisitions If you want to set the duration of the acquisition instead of the number of points, skip step To set the number of points for the acquisition, 6a. Use the up/down or left/right arrow keys to select Points. 6b. Press ENTER to access the points edit box. 6c. Use the left/right arrow keys to select the desired digit and the up/down arrows to increase or decrease the flashing value. Then confirm by pressing ENTER. See table on page 45 for the maximum number of points that can be set. As you change the number of points, the duration is automatically set as a function of the sampling rate. 7. To set the duration of the acquisition, 7a. Use the up/down or left/right arrow keys to select Duration. 7b. Press ENTER to access the duration edit box. 7c. Use the left/right arrow keys to select the flashing digit of the duration and the up/down keys to increase or decrease the flashing digit. You can enter a duration from 00h00m01s to 99h59m59s. As you change the duration, the number of points is automatically set as a function of the sampling rate. 7d. Confirm the duration by pressing ENTER. 8. Enable the acquisition as explained in Programming Timed Acquisitions on page 46. The TG marker will be displayed when the trigger is activated. Note: It is not possible to set the duration when programming a high-rate, triggered acquisition. IMPORTANT Starting an acquisition erases all acquisition data in memory. 52 PM-1600

63 Programming Acquisitions Saving a Program Configuration Saving a Program Configuration Once you have defined the parameters for a data acquisition, whether using timed or triggered mode, it is possible to save the configuration of the program. Up to three program configurations can be saved and recalled. The following parameters are saved: trigger status and conditions (source, type, and level) delay duration sampling rate number of points To save a program configuration, 1. Before enabling the acquisition by pressing Start Program (as explained in Programming Timed Acquisitions on page 46, or in Programming Triggered Acquisitions on page 49), use the up/down or left/right arrow keys to select Save. The current program configuration number is displayed. Note: (Mod.) following Save indicates that a recalled program configuration has been modified. 2. Press ENTER to access the program configuration edit box. 3. Use the up/down arrow keys to set a program configuration number from 1 to Confirm the new program configuration by pressing ENTER. It takes a few seconds to save a program configuration. High-Speed Power Meter 53

64 Programming Acquisitions Recalling a Program Configuration Recalling a Program Configuration Once you have saved a program configuration, you can recall it at any time. To recall a configuration, 1. Set the power measurement parameters as required (see Customizing the PM-1600 Display on page 83). 2. Press Program to access the Program menu. 3. Use the up/down or left/right arrow keys to select Recall. The current program configuration number is displayed. 4. Press ENTER to access the program configuration edit box. 5. Use the up/down arrow keys to select the required configuration number. 6. Confirm by pressing ENTER. 54 PM-1600

65 7 Performing Typical Tests with Your PM-1600 To make accurate, meaningful, and repeatable power measurements, it is important to consider the following points: Connectors, fiber ends, ports, and detectors should be clean at all times. A null measurement should be performed prior to each user session or whenever there is a significant change in ambient temperature. To perform a null measurement, see Nulling Electrical Offsets on page 11. The optical source should be stable. Appropriate test jumpers, connectors, and adapters must be used. Once a reference has been taken, ensure that the setup remains stable. To take a reference, see Measuring Relative Power on page 16. Since optical losses vary according to the launch, receive conditions, and fiber type, controlling these conditions with mode filters and strippers is essential. High-Speed Power Meter 55

66 Performing Typical Tests with Your PM-1600 Performing Absolute Power Measurements Performing Absolute Power Measurements Absolute power measurements are necessary when performing system or component monitoring, quality control, system, or component acceptance and troubleshooting. To perform an absolute optical power measurement, 1. Perform an offset nulling. 2. Using an appropriate test jumper and connector adapter, connect the DUT to the detector port. PM-1600 HIGH-SPEED POWER METER PM-1600 Store Recall Program Null Display ENTER Setup Analog Out C1 C2 Ext. Trig dbm/w db W/W Ref Chan λ Range Avg Shift DUT 3. Adjust the power meter to the correct wavelength, db or W/W correction factor, and set the display unit to dbm or W. 4. The absolute optical power can now be monitored and recorded. Note: Using a PM-1620, absolute power can be simultaneously measured for each independent channel. Simply apply each step of the above procedure to all used channels. 56 PM-1600

67 Performing Typical Tests with Your PM-1600 Measuring Insertion Loss Measuring Insertion Loss To ensure accurate measures for the insertion loss of a fiber-optic component, use a light source (FLS-2100) and a PM-1600 Power Meter. To measure insertion loss, 1. Using two appropriate test jumpers and a bulkhead adapter, connect the source to the power meter as shown below. This setup will be used to record a reference value. PM-1600 HIGH-SPEED POWER METER FLS-2100 OPTICAL LIGHT SOURCE PM-1600 Store Recall Program FLS-2100 Store Null Display ENTER Setup Analog Out C1 C2 Ext. Trig Attenuation Setup ENTER dbm/w db W/W Ref Chan On/Off CW Up λ Range Avg Shift λ Modulation Down ACTIVE Test jumper Bulkhead adapter Test jumper 2. Adjust the source and power meter to the appropriate wavelength. 3. Activate the source and select a suitable power output. IMPORTANT The absolute power output value is not particularly important when measuring insertion loss. However, it is very important that the power level used for taking the reference measurement be identical to the power level used during the insertion loss measurement. High-Speed Power Meter 57

68 Performing Typical Tests with Your PM-1600 Testing Instrument Linearity 4. On the PM-1600 Power Meter, set the measurement units to db or dbm and press Ref. The reference value has now been taken and the display should read db. 5. Replace the bulkhead adapter with the DUT as shown in the following figure. PM-1600 HIGH-SPEED POWER METER FLS-2100 OPTICAL LIGHT SOURCE PM-1600 Store Recall Program FLS-2100 Store Null ENTER Setup Analog Out C1 Ext. Trig Attenuation Setup ENTER dbm/w db W/W Ref Display On/Off CW Up λ Range Avg Shift λ Modulation Down ACTIVE DUT Test jumper Test jumper 6. The insertion loss of the DUT is the relative measurement as displayed by the PM For best results, ensure that the setup remains stable. Testing Instrument Linearity As stated in Measuring Insertion Loss on page 57, absolute power levels are not particularly significant when measuring the insertion loss of a fiber-optic component. In calculating insertion loss, we are essentially measuring the difference between the power in and out of a DUT. To accurately measure delta power, instrument linearity is very important. The PM-1600 High-Speed Power Meter is specified to be very linear, down to 55 dbm. Not only is the PM-1600 ideal for measuring insertion loss, it is also suitable as a reference instrument for determining the linearity of other fiber-optic components such as attenuators, other power meters, and optical detectors. 58 PM-1600

69 Performing Typical Tests with Your PM-1600 Testing Instrument Linearity When verifying instrument linearity, a linear variable attenuator (e.g., FVA-3100) is also required. Before verifying the linearity of an optical detector, you must confirm the linearity of the attenuator being used. Confirming the Linearity of the Attenuator Being Used Before getting started, you need a stable source (FLS-2100), a variable attenuator, a PM-1600, two test jumpers, and appropriate connector adapters. To confirm the linearity of the attenuator being used, 1. Connect the instruments as shown below. FLS-2100 OPTICAL LIGHT SOURCE FLS-2100 Store Attenuation Setup ENTER On/Off CW Up λ Modulation Down ACTIVE PM-1600 HIGH-SPEED POWER METER FVA-3100 VARIABLE ATTENUATOR PM-1600 Store Recall Program FVA-3100 Program Null ENTER Setup Analog Out C1 Ext. Trig Step Setup ENTER dbm/w db W/W Ref Display Abs Offset Up Shutter λ Range Avg Shift λ Rel Down Attenuation In Out 2. With all instruments set to the same wavelength and the attenuator set to minimum attenuation, take a PM-1600 reference measurement and switch to relative display. Also, switch the attenuator to relative display mode. High-Speed Power Meter 59

70 Performing Typical Tests with Your PM-1600 Characterizing an Optical Switch 3. At this time, both the attenuator and power meter will display db. Increase the attenuation using constant step sizes while recording the values from both displays (attenuator and power meter) at each step. Continue until the power meter indicates around 55 db. The recorded values at each step should follow within permitted tolerances. If the values do not follow, there is a problem with the equipment setup or with one of the instruments. Before proceeding any further, the problem must be solved. Testing the Linearity of an Optical Detector Once the test configuration and instruments are properly set up (see Confirming the Linearity of the Attenuator Being Used on page 59), you can start testing for component linearity. To test the linearity of the detector, 1. Disconnect the PM-1600 from the circuit as shown in the figure on page 59 and replace it with the detector being tested. 2. Reset the attenuator to minimum attenuation. 3. Increase the attenuation on the attenuator with constant step sizes, while recording the output read by the detector at each step. 4. When completed, the data can be analyzed to determine the linearity of the detector. Characterizing an Optical Switch The high sampling rate, fast stabilization, and trigger capability of the PM-1600 can be used simultaneously to easily characterize optical switches. The figure displayed in Testing Repeatability section on page 61 displays a simple test station for a 1 x 2 optical switch. A light source is connected to the optical switch common terminal. Each optical output of the switch is connected to a detector of a PM-1600 Dual-Channel Power Meter. This test setup can be used to test both the repeatability and the settling time of the 60 PM-1600

71 Performing Typical Tests with Your PM-1600 Characterizing an Optical Switch optical switch. For the latter test, the electrical signal that is used to command the switch is also connected to the external trigger input of the PM Testing Repeatability The procedure to test the repeatability of an optical switch is relatively simple. First, a reference measurement must be taken on each channel. Repetitive transitions of the switch must then be performed and the total deviation from the reference points will be considered as switch repeatability. To test repeatability, 1. Connect the instruments as shown below. PM-1600 HIGH-SPEED POWER METER FLS-2100 OPTICAL LIGHT SOURCE PM-1600 Store Recall Program FLS-2100 Store Null Display ENTER Setup Analog Out C1 C2 Ext. Trig Attenuation Setup ENTER dbm/w db W/W Ref Chan On/Off CW Up λ Range Avg Shift λ Modulation Down ACTIVE DUT (optical switch) Control signals 2. Set the power meter channels to the same wavelength as the source. 3. Set the power meter channels to Autorange mode. 4. Set the switch to the first position and take a reference measurement on the power meter, selecting the active channel (the channel in which the switch has a minimum insertion loss). 5. Set the switch to the second position and take a reference measurement on the power meter, selecting the active channel. High-Speed Power Meter 61

72 Performing Typical Tests with Your PM-1600 Characterizing an Optical Switch 6. Change the switch position from one channel to the other. For each channel, take note of the relative power measurement when the channel is active. 7. For each channel, the total switch deviation will be the highest positive deviation minus the highest negative deviation relative to the original reference (taken at step 4). The repeatability of the switch insertion loss may be expressed as ± (total deviation in db)/2. Testing the Settling Time The triggering and fast stabilization of the PM-1600 can be used to capture fast power transitions. A good example of this is the optical switch settling time measurement. When an electrical control signal for the switch is available, a settling time including the electronics response time can be measured. This is done by controlling the PM-1600 remotely to easily retrieve the acquisition data (see Controlling the PM-1600 Automatically or Remotely on page 67). To measure the settling time, 1. Connect the instruments as shown below. PM-1600 HIGH-SPEED POWER METER FLS-2100 OPTICAL LIGHT SOURCE PM-1600 Store Recall Program FLS-2100 Store Null Display ENTER Setup Analog Out C1 C2 Ext. Trig Attenuation Setup ENTER dbm/w db W/W Ref Chan On/Off CW Up λ Range Avg Shift λ Modulation Down ACTIVE DUT (optical switch) Control signals 2. Set the power meter channel to the same wavelength as the source. 62 PM-1600

73 Performing Typical Tests with Your PM-1600 Using the External Trigger 3. Set the power meter channels to the proper manual range, making sure that no saturation occurs on the active channel. 4. Select the highest Single sampling rate (4096 samples per second). 5. Set the acquisition to be externally triggered. 6. Set the optical switch to initial position. 7. Start the acquisition. 8. Activate the electrical control signal, which acts as a trigger for the PM The PG marker, in measurement mode, will be displayed until the switch transition is totally acquired. 9. Retrieve the data by remote control and determine the switch time from the initial channel to the target channel. 10. Repeat steps 6 to 9 for each transition to be characterized. This chapter describes how to use the external trigger and analog output of the PM-1600 High-Speed Power Meter. Both the external trigger and analog output are easily accessible from the front panel of the power meter and use standard BNC connectors. Using the External Trigger The external trigger is used to synchronize or stimulate the acquisition of power measurements with an electrical signal (TTL level). Acquisitions at up to 4096 Hz can be performed. The use of an external trigger requires a programmed acquisition and selection of a manual power range. High-Speed Power Meter 63

74 Performing Typical Tests with Your PM-1600 Using the External Trigger Connecting a TTL Source to the External Trigger A synchronizing signal from a signal generator or from a control circuit may be connected to the external trigger input of the PM-1600 if it does not exceed TTL levels. The illustration below displays a typical signal generator connection setup. Signal generator External trigger input n GHz 6.00 dbm PM-1600 HIGH-SPEED POWER METER PM-1600 Null Display Store Recall Program ENTER Setup Analog OutC1 C2 Ext. Trig dbm/w db W/W Ref Chan λ Range Avg Shift Optical power input DUT (e.-o. component) Optical input Optical output External Trigger and Data Acquisition To prepare an externally triggered acquisition, 1. Make sure a sampling rate from 512 Hz to 4096 Hz and a manual power range are selected. 2. Follow the instructions in Programming Triggered Acquisitions on page When you enable the externally triggered acquisition with Start Program, the acquisition will wait for the voltage transition to occur before storing the data in memory. If a delay was set, the acquisition will first wait until the countdown has expired and then until the trigger condition is met. 64 PM-1600

75 Performing Typical Tests with Your PM-1600 Using the Analog Output Using the Analog Output The analog output provides an electrical signal proportional to the optical power input on the detector. On a dual-channel high-speed power meter, this is only available for channel #1. The analog output signal is the redirection of the signal after the first amplification stage. Do not use the analog output while in Autorange mode (see Setting Measurement Range on page 22) because the gain scales of the first amplification stage are constantly changed to optimize signal-to-noise ratio. The following two figures illustrate typical use of the analog output. Digital oscilloscope PM-1600 HIGH-SPEED POWER METER PM-1600 Null Display dbm/w db W/W Ref Chan Store Recall Program ENTER Setup Analog OutC1 C2 Ext. Trig λ Range Avg Shift Analog output Data logger PM-1600 HIGH-SPEED POWER METER PM-1600 Null Display dbm/w db W/W Ref Chan Store Recall Program ENTER Setup Analog OutC1 C2 Ext. Trig λ Range Avg Shift Analog output High-Speed Power Meter 65